The present invention relates to a pattern measuring method and a charged particle radiation apparatus, and more particularly to a method and apparatus for measuring a displacement between a line chart based on design data and a charged particle radiation image.
There are known technologies for detecting a pattern defect on a semiconductor wafer or a photoreticle by using semiconductor circuit design data. Since the circuit design data shows an ideal shape of a subject semiconductor pattern, it is possible to evaluate the performance of a semiconductor manufacture process through comparison with this pattern. JP-A-2001-338304 (corresponding to U.S. Pat. No. 6,868,175) and JP-A-2002-31525 (corresponding to US 2002/0015518) disclose that a deformation amount of a pattern from design data is detected by detecting edges of a subject inspection pattern and a reference pattern and comparing the detected edges.
Many semiconductor devices have a multilayer structure nowadays, and a superimposition precision between layers is an important measuring item. A performance of a semiconductor device depends largely upon a displacement between upper and lower layers of the semiconductor device including a composite pattern of the upper and lower layers. The displacement is therefore a very important evaluation item. However, the above-cited JP-A-2001-338304 (corresponding to U.S. Pat. No. 6,868,175) and JP-A-2002-31525 (corresponding to US 2002/0015518) do not intend to measure a displacement between patterns constituting a multilayer pattern.